I recently purchased an ADL 600 and a 192. What is the proper cable configuration coming out of the ADL 600 and into the 192? I know not to use channels 1 or 2 into the 192. Can I go XLR out of the ADL600 and XLR into channels 3-8 on the 192? Is it better to have a cable that has XLR out and TRS in? Thank you for your help.

TRS in to the 192 is what you want (jacks 3-8). The trs plug will cause a bypass of the preamps, not adding another stage for gain. XLR isn't a game changer, but using that you have to worry about another gain stage.